Publications

mercury exposure in songbird communities along an elevational gradient on whiteface mountain, adirondack park (new york, usa).	mercury (hg) is a potent neurotoxin that biomagnifies within food webs. adverse effects have been documented for avian species related to exposure of elevated hg levels. high elevation, boreal forests generally receive higher atmospheric hg deposition and regional studies have subsequently identified elevated blood hg concentrations in songbird species inhabiting these montane habitats. the overall goal of this study was to investigate spatial and seasonal hg exposure patterns in songbird specie ...	2020	32232628
overtone-based pitch selection in hermit thrush song: unexpected convergence with scale construction in human music.	many human musical scales, including the diatonic major scale prevalent in western music, are built partially or entirely from intervals (ratios between adjacent frequencies) corresponding to small-integer proportions drawn from the harmonic series. scientists have long debated the extent to which principles of scale generation in human music are biologically or culturally determined. data from animal "song" may provide new insights into this discussion. here, by examining pitch relationships us ...	2014	25368163
surveillance for ixodes pacificus and the tick-borne pathogens anaplasma phagocytophilum and borrelia burgdorferi in birds from california's inner coast range.	we investigated the involvement of birds in the ecology of the western black-legged tick, ixodes pacificus, and its associated zoonotic bacteria, borrelia burgdorferi and anaplasma phagocytophilum, at two interior coast-range study sites in northern california. anaplasma phagocytophilum, the agent of granulocytic anaplasmosis (ga), and b. burgdorferi s.s., the agent of lyme disease (ld), are tick-borne pathogens that are well established in california. we screened blood and ticks from 349 indivi ...	2014	24690191
integrative tracking methods elucidate the evolutionary dynamics of a migratory divide.	migratory divides, the boundary between adjacent bird populations that migrate in different directions, are of considerable interest to evolutionary biologists because of their alleged role in speciation of migratory birds. however, the small size of many passerines has traditionally limited the tools available to track populations and as a result, restricted our ability to study how reproductive isolation might occur across a divide. here, we integrate multiple approaches by using genetic, geol ...	2014	25535561
how migratory thrushes conquered northern north america: a comparative phylogeography approach.	five species of migratory thrushes (turdidae) occupy a transcontinental distribution across northern north america. they have largely overlapping breeding ranges, relatively similar ecological niches, and mutualistic relationships with northern woodland communities as insectivores and seed-dispersing frugivores. as an assemblage of ecologically similar species, and given other vertebrate studies, we predicted a shared pattern of genetic divergence among these species between their eastern and we ...	2013	24255819
use of data on avian demographics and site persistence during overwintering to assess quality of restored riparian habitat.	monitoring responses by birds to restoration of riparian vegetation is relatively cost-effective, but in most assessments species-specific abundances, not demography, are monitored. data on birds collected during the nonbreeding season are particularly lacking. we captured birds in mist nets and resighted banded birds to estimate species richness and diversity, abundance, demographic indexes, and site-level persistence of permanent-resident and overwintering migrants in remnant and restored ripa ...	2012	22443304
reduced density and nest survival of ground-nesting songbirds relative to earthworm invasions in northern hardwood forests.	european earthworms (lumbricus spp.) are spreading into previously earthworm-free forests in the united states and canada and causing substantial changes, including homogenization of soil structure, removal of the litter layer, and reduction in arthropod abundance and species richness of understory plants. whether these changes affect songbirds that nest and forage on the forest floor is unknown. in stands with and without earthworms in the chequamegon-nicolet national forest, wisconsin (u.s.a.) ...	2011	21797927
quantitative magnetic resonance analysis and a morphometric predictive model reveal lean body mass changes in migrating nearctic-neotropical passerines.	most studies of lean mass dynamics in free-living passerine birds have focused on old world species at geographical barriers where they are challenged to make the longest non-stop flight of their migration. we examined lean mass variation in new world passerines in an area where the distribution of stopover habitat does not require flights to exceed more than a few hours and most migrants stop flying well before fat stores near exhaustion. we used either quantitative magnetic resonance (qmr) ana ...	2011	21079970
west nile virus surveillance in east baton rouge parish, louisiana.	west nile virus (wnv) was detected for the first time in louisiana in the fall of 2001. surveillance data collected from east baton rouge parish in 2002 were examined to establish baseline data on wnv activity, to support the current design of disease surveillance programs, and to target vector control efforts in the parish. the first indications of wnv activity were from a dead northern cardinal collected in february and from a live male cardinal sampled on 14 march. in mosquito pools, wnv was ...	2007	17536365
an avian contribution to the presence of ixodes pacificus (acari: ixodidae) and borrelia burgdorferi on the sutter buttes of california.	birds from 45 species were sampled during three spring seasons from an isolated canyon on the sutter buttes in california for the presence of subadult stages of ixodes pacificus cooley & kohls, and for infection with borrelia burgdorferi johnson, schmid, hyde, steigerwalt & brenner. these birds were found to have an infestation prevalence of 45%, a density of 1.7 ticks per bird, and an intensity of 3.8 ticks per infested bird. there was a significant difference in the i. pacificus infestations b ...	2006	16619623
a field validation of plasma metabolite profiling to assess refueling performance of migratory birds.	plasma metabolite profiling offers a potential means to assess stopover refueling performance of migratory birds from a single capture. however, this method has not previously been validated where site quality has been determined independently using analysis of capture data. we captured and blood sampled six passerine bird species refueling at known high-quality (base) and low-quality (tip) sites at long point, ontario, canada. plasma triglyceride, an indicator of fat deposition, was higher at t ...	2005	15702470
comparison of the retinal structure and function in four bird species as a function of the time they start singing in the morning.	we postulated that the retinas of bird species that are the earlier singers are more sensitive to low light conditions than species that sing closer to sunrise. the selected species were the american robin (turdus migratorius) and the hermit thrush (catharus guttatus) as early singers, the common grackle (quiscalus quiscula) and the mourning dove (zenaida macroura) which join the dawn chorus near sunrise. scotopic electroretinogram (ergs) intensity-response functions were obtained from anestheti ...	2005	15703474
a species-specific acoustic cue for selective song learning in the white-crowned sparrow.	song learning in birds is paradoxical. without tutoring, songbirds do not develop normal songs. yet despite this inability, birds possess extensive foreknowledge, in a mechanistic sense, about the normal song of their species. when given a choice of tape recordings, young, näive songbirds select sounds of their own species for imitation. we tape-tutored white-crowned sparrows, zonotrichia leucophrys oriantha, with a set of manipulated songs to investigate whether the introductory whistle univers ...	2000	11007638
re: congruence and phylogenetic reanalysis of perching bird cytochrome b sequences.	in a study of the phylogenetic relationships among perching bird mtdna sequences, edwards et al. (1991; proc. r. soc. london ser b. 243: 99-107) sequenced part of the mitochondrial cytochrome b gene from 13 perching birds (passeriformes) and a woodpecker outgroup. however, recently the validity of part of the sequence of the hermit thrush (catharus guttatus) in that study has been questioned. to determine the effect of inclusion of this apparently chimeric sequence on the conclusions of the orig ...	1997	9126569
retraction of a thrush (catharus guttatus) cytochrome b sequence.		1996	8920253